What about using a regular 14-inch lcd monitor for OHP???

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I know this has been discussed very briefly but for the most part it was discussed about using it in DIY projectors. And I understand why it doesn't work in that situation since it would require a huge lens to focus it. I'm thinking it would work great for an XGA OHP setup. I did read a post with a failure in making something like this work but somebody out there with some knowledge of repairing lcd panels might be able to help. I understand that in most cases the 14-inch lcd screen would be too big but if you get a OHP with a decent size stage aperture wouldn't this work? I believe the biggest problem is extending the ribbon cable away from behind the screen. Are there any difference with overhead lcd panels and desktop panels that make it incompatible with OHP's besides one being much smaller and self enclosed? I figure I don't want normal TV input anyways so i don't care about not having s-vhs inputs and these screens are signifigantly nicer. And now with the rising prices of those older panels i can see it coming to a point where people are paying around $300 for these very dated lcd's. I guess my biggest question in this ramble is if I used a larger panel on my OHP would i lose lumens in my projected picture? That's it....thanks for listening. Maybe I can find out more in the next few weeks when I start my job at a computer repair store :)


MMMMM.....XGA, better contrast, and better response times
 
The driver board still could be a problem if it goes right through the middle of the screen. As far as that goes the only monitor I have heard success from is the Viewsonic VG150 which is about $300 a bit much for me right now. Good specs though 350:1 contrast,1280*768 res.
 
Do you happen to know if the person who used it is on this board? Wow, I am just amazed at how little discussion this generates. These panels are infinitely better then the ohp panels and people have already given up on them because of the ribbon cables and such. How about an lcd repair shop? I would bet they could get ahold of larger cable and maybe even attach the driver board out of the way. I do realize the biggest issue is price, but you can't get the sharp qa-2500 for under $300. And i can guarantee you the quality would be far less with this panel. Only over the last few years has contrast, reponse times and colors been greatly improved. So what am I saying? I'm saying there's nothing wrong with getting overhead panels and using them. They are a nice, safe and cheap alternative to getting a real projector. But with prices only rising on these older panels....soon we'll need an alternative and if we can make the larger panels work with an OHP setup we won't be out of luck when the ohp panels run out. Maybe this will spur some more discussion.....
 
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Havix321

There was quite a lot of discussion re viewsonic monitors in the part 1 video projector thread. jjasniew was a pioneer in this as well.

Search for viewsonic

or search for a member jjasniew

This will show the info on the board.

The consensus was the cables were so thin they caused real problems moving the driver boards out of the way but one or two guys were succesful.

You are right what you say. We should be looking at alternative panels. I have been in contact with a Taiwanese company who will sell a one off 10 inch LCD monitor with S-video and SVGA computer in for $270 US + shipping but they will not/can not answer my questions about moving the driver boards. Maybe my Taiwanese is no good.

If the board can be moved its not a bad panel. It might be chip on glass in which case it would be impossible to move. I have a pdf if anyone wants it and the company name and contact person Charlene. Charlene is lovely.

There are hundreds, thousands of good panels from South Korea, Taiwan, China and info freely available and they all seem eager to sell but just can't get that vital info re shifting the drivers. Several offer "samples" You have to tell them why they should send you a free or low priced sample. So if you have the Midas touch its worth a shot. The place to look is

Google global sources

Of all the panels from that area that I have seen there is only one that is similar to a regular projection panel and that is a combination unit. You have to buy the OHP as well.

Another panel worth a look

Google lcd-252

$85 US + shipping $25 anywhere.

The thing about this one is it shows the works hanging down out of the way. Video in no computer in from memory. NTSC and PAL
Its not complete. You have to add the contrast, brightness,tint controls yourself (simple job).
 
Yep, i did a search and see that a few people had success with the VG150. It's really too bad that the cabling is so fragile. I wonder if the cables are specific to each panel or manufacturer. If only one of us could get in contact with someone who has the technical understanding and technical papers from popular desktop lcds. And maybe this is a stupid question, but why can't the cable just simply be replaced or repaired if damaged? Is it because there isn't an alternative to the cabling or is it because it's impossible to repair and must be reordered and the companies won't sell to us directly? These are all questions that should/need to be answered. The 10-inch lcd panel you mention sounds very interesting if you can find out about it's driver board positioning. I would love to see the pdf you have on this panel. And I also agree that finding a decent panel for cheap, might take getting them from obscure sources like companies in South Korea, Taiwan, and China. But I am wary of buying an lcd from these companies without proper reviews that can confirm the specs listed. Also, it always helps when I can speak with people that know the English language :) But I'm glad other people are looking into this as well. I guess we have to keep posting our experiences. In my case I've started to email lcd repair companies to find more info on driverboard placement and more info on flex cables.
 
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havix321

Ok will send the pdf.

The specs on the lcd-252 agreed are not very good you would be surprised how good that is for video. but the picture is useful. I send it to people as an example of having the driver board movable. So far not one has replied on that question. I guess they know the cables are fragile.

The main problem is the connections from the LCD to the electronics. There are so many they dont use a connector, the very thin foil is glued or somehow attached directly to the LCD not using a plug. Try and get in with a tv technician and see one stripped down. You might be able to get a few dead ones to experiment with how to dismantle.

You will be very very surprised dealing with companies in those areas mentioned. They are agressive about getting more market share from Japan which you can only do with good product and service and every single company I have emailed has an immaculate English speaking front person.

BTW I asked a moderator to remove your email address from your post. Hope you dont mind. Web spiders cruise around all the time and pick up exposed emails and put you on a junk mail listing. I thought you would not want that.
 
Hmm 270 + shipping is about the price of a vg150 or more. Yes the cables are super super sensitive. You pull or flex a ribbon cable a few too many times and it's dead :( . Many places out of country want you to buy a ton of panels at a time too. My suggestion with any flex cable is to have it supported so there is minimal strain and to set it in one place and don't move it around.
 
I got the pdf. Thanks. My thoughts on this 10-inch board are mixed. It's size would make it easier to use over a 15-inch lcd monitor. And as we all know specs on many of these lcds are misleading. So the ones that claim 16-million colors often come up short. These panels on the other hand say 262,144. Now if these are accurate and it has decent contrast then the picture might be good. Almost certainly better then the lcd overhead panels we are seeing. The bad things I see, is the resolution which is still only 800x600. Not bad but if we aren't guaranteed easy access to removing the driver board to a safe position what makes this option better? I think we need to start sending emails to viewsonic, to HP, to NEC and Sony. I think everyone is agreed on this. I'm getting very anxious about buying an lcd monitor but i don't want my $300-$400 to fly out the window because I damaged a little cable or the driver board is not movable. I start work on monday at computer renassaince, so maybe I can ask around and see if they have any broken lcd monitors, or to keep an eye out for one. Here's a comparison of lcd monitors. I think the HP looks mighty tasty. http://www.tomshardware.com/display/02q1/020322/index.html
 
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